Miscellaneous Productions

MakerSlide End Plates / CNC Cutting 8mm Aluminium

Just bear with me I have a little bit of a cold at the moment and I’m making lots of stupid mistakes, so it’s the perfect time to be planning to do something on the CNC machine.

I love this type of wrapping. It’s just so intense.

Coz aluminium is not waterproof is it?

So this is the material I am planning to us replace the end plates and it’s 8mm thick and it’s about 350mm by 240mm. So I’m just going to punch those numbers into my software.

So what I was thinking – I would drill the holes first and then I’d screw that down and then finish around the edge. I’m also not sure how… I mean it does feel like it’s got a grain to it and I don’t want to make some going this way and some going that way if that makes a difference? But I guess this isn’t wood I shouldn’t treat it like wood. Anyway I’m going to set this all up and the next thing you’ll see is me panicking.

This is the bit I’ll be using. It’s a 4 flute carbide square cutter I think it’s called. Don’t know what it’s called square because it looks round to me and I’m going to be using it with this adaptor which steps down a 1/4″ collet to 4mm – which is how thick this is. Again I bought this from China. I mean it’s just affordable – that’s the point. It seems to work. You know I’m not milling things to go into outer space. Ok so I’m going to work out the feed rate for this bit in relation to the router that I’m using which is the Bosch GFK I think it is, 600. It doesn’t have variable speed and it runs at 33,000 RPM. So I converted some data from a website which – I had to do this into metric so I could understand it. So I’m just going to estimate roughly. So I’ve got to take the chip load and times that by the cutting diameter, times by the number of flutes and then by the spindle speed, and then divide it by 25.4 which will give me the feed rate in mm/min. Ok. So I’m just going to do that. I’m going to go for 0.1016 times 4, times 4, times 33,000 divided by 25.4. Supposedly my feed rate on this machine should be able to go at 2,112. So we’ll round it down to 2000 and I’ll use that for the test, to see how it goes. I’m hoping this was a conservative equation that I borrowed from I think it was make mag or something like that. I found an equation which indicated how to do that and I’ll provide link as always in the description bellow.

So I’m going to do a test though first. I’m not going to go straight away and cut on the piece that I bought because from my experience I generally mess up.

I used a little bit of isopropanol alchonol (sic) alcohol alchonol? I think I’m going to change the feed rate to maybe a third or less. Yeah it’s 5.22, that’s pretty good and I just want to check the depth and it should have gone down 4mm. Holy hell it’s bang on 4mm.

So I had a few problems with the big getting stuck in the aluminium because of the speed at which it was spinning, primarily. I’m just going to let you hear the machine struggling.

Ok so I realised what I did wrong previously and I added an basically put an extra 0 on the feed rate. Which meant it went like a rocket but it seems to be cutting quite accurately despite that monumental cock-up by myself, and I’m going to have another attempt. Considering how fast it was going I am amazed that it managed to cut as deep as it did and the only thing that had resulted in it breaking across like that was because the chip load was just so high it clogged up the flutes. And then pulled the actual bit into the aluminium. It didn’t break the bit which is surprising again.

I’ve lined up the aluminium again so it’s square with the front of the machine and I’m going to set the home position about there. This time it’s going a lot slower. I set the feed rate to about 300 mm/min. I’m not sure if by adding some sort of cutting solution in the form of WD40 or Isopropanol I’m actually making the chips kinda stick to the material, and stay into the cutting channel?

This is the one I cut out on the machine. Em it looks pretty good. The finish is pretty nice. The height is correct width is a mm short so I don’t know what that’s happen? Maybe the belt has become a little bit slack since I’ve not been using it as much. I think retrospect I should have maybe used thinner aluminium and laminated it together. It’s cheaper to work with 3mm, it produces less heat when your cutting it and easier to cut. I think trying to go for the 8mm in one go is a bit ambitious. The overall job took about an hour to do, erm since then I’ve made a second one which I actually did on the router table. And I used the original as a template. I’m going to save that for another video – it wasn’t as safe as I though it would be and I’ll explain some of the processes that went involved in that. In addition to that I’ve also made a adaptor ring which fits into the spindle mount like this and allows me to use a variable speed router, so I’ll be able to cut a couple more end plates out using a slightly slower spindle speed. So I don’t have to worry about the bit overheating. You’ll be able to expect a couple new videos coming up soon where I try to make the other two plates, where I’ll be increasing the cutting height of the CNC machine as well as another video where I make this adaptor ring, so I can use a variable speed router on the CNC machine. So sorry I haven’t been posing as frequently as I was last year and thanks for watching.